External cellular heat sink structure

ABSTRACT

An external cellular heat sink structure includes a base and a heat dissipating body integrally formed on the base. The heat dissipating body includes a plurality of hollow cellular units, wherein the neighboring cellular units are connected together, and each cellular unit has at least two openings for communicating the connected cellular units with each other. Thus, the cellular unit can provide the larger dissipation area, and each opening can let the gas pass and disperse the gas so that the time and possibility for the gas to contact the heat dissipating surface are lengthened and increased, respectively, and the heat dissipation efficiency is increased.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a technological field of a heat sink, and moreparticularly to an external cellular heat dissipating structure, whichcan be applied to a LED road lamp, a solar thermoelectric conversionapparatus or any other apparatus or element requiring heat dissipationby way of heat transfer.

2. Related Art

A typical light-emitting diode (LED) apparatus, such as a LED road lamp,generates a lot of heat with the elapse of time after being turned on.The high-temperature causes poor effects, such as the lowered workingefficiency and endurability, to the LED apparatus. Thus, the typical LEDapparatus is almost equipped with a heat sink or a heat dissipatingsystem to perform the heat dissipation. The frequently seen heat sink iscomposed of many heat dissipating fins, which are arranged in parallelat the same level so that the heat is dissipated to the atmospherethrough the surface of each heat dissipating fin. In addition, theflowing air streams can take the heat away through the gaps between theheat dissipating fins.

Because the heat sink is exposed to the atmosphere, the rain, dust orleaves may directly fall on the heat dissipating fins. Therefore, inorder to prevent the problems, such as the unpredictable leakagecurrent, the short-circuit condition or the fan failure, the outdoorheat sink is not suitable for the working in conjunction with the fan.

One method for increasing the heat dissipation efficiency is to increasethe number of the heat dissipating fins to enlarge the dissipation area.However, increasing the number of heat dissipating fins would decreasethe gap between the neighboring heat dissipating fins. In addition, theparallel and contour structure of the heat dissipating fins disables theheat inside the inner heat dissipating fins from being easilydissipated. Thus, the heat accumulation is produced, and the heatdissipation effect cannot be substantially enhanced.

Also, the too-dense heat dissipating fins increase the possibility ofthe accumulation of the dust or leaves, and disable the flowing airstreams from easily passing through the gaps between the heatdissipating fins so that the heat dissipation efficiency of the heatsink is poor.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an externalcellular heat sink structure with the larger dissipation area, so thatthe flowing air streams can flow within the heat sink in many directionsand the heat sink has the higher heat dissipation efficiency.

According to the above-identified object and effect, the inventiondiscloses an external cellular heat sink structure including a base anda heat dissipating body integrally formed on the base. The heatdissipating body includes a plurality of hollow cellular units. Theneighboring cellular units are connected together, and each cellularunit has at least two openings for communicating the connected cellularunits with each other.

Thus, the cellular unit can provide the larger dissipation area, andeach opening can let the air streams or gas streams pass and dispersethe air streams or gas streams so that the time and possibility for theair streams or gas streams to contact the heat dissipating surface arelengthened and increased, respectively, and the heat dissipationefficiency is increased.

Further scope of the applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the presentinvention, are given by way of illustration only, since various changesand modifications within the spirit and scope of the present inventionwill become apparent to those skilled in the art from this detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention.

FIG. 1 is a pictorial view showing a first embodiment of the invention.

FIG. 2 is a schematic plane view showing the first embodiment of theinvention.

FIG. 3 is a schematic plane view showing a second embodiment of theinvention.

FIG. 4 is a schematic illustration showing a top-view structure and gasflow directions of the invention.

FIG. 5 is a schematic illustration showing another top-view structureand gas flow directions of the invention.

FIG. 6 is a schematic illustration showing still another top-viewstructure and gas flow directions of the invention.

FIG. 7 is a pictorial view showing that one side of an opening of thecellular unit of the invention has an arced wall edge.

FIG. 8 is a schematic illustration showing another structure accordingto a third embodiment of the invention.

FIG. 9 is a schematic illustration showing that the invention is appliedto a structure of a LED road lamp.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings,wherein the same references relate to the same elements.

Referring to FIGS. 1 and 2, a heat sink 10 includes a base 12 and a heatdissipating body 14 integrally formed on the base 12.

In detail, the heat dissipating body 14 includes a plurality of hollowcellular units 16, wherein the neighboring cellular units 16 areconnected together. In addition, the top edge of the heat dissipatingbody 14 is formed with an arced structure 32 (see FIG. 2) having twosides and a middle portion higher than the two sides.

As shown in FIG. 3, the top edge of the heat dissipating body 14 may beformed with a continuous arced wavy structure 34 having peaks that maybe located at the same level.

According to the above-mentioned disclosure, the peaks of the arced wavystructure 34 may be located at different levels. For example, the peakat the middle position is located at a higher level, and the peak at thelateral side is located at a lower level.

As shown in FIGS. 1 and 4, the cellular unit 16 may be a hexagonalcolumn structure, and at least two structure surfaces are selected frommultiple structure surfaces of each cellular unit, and each of theselected structure surfaces is formed with an opening 18. In otherwords, the cellular unit 16 may have two openings 18 extending in twodifferent directions. In detail, the neighboring cellular units 16 maycommunicate with one another through the openings 18 formed on thestructure surfaces.

As shown in FIG. 5, the cellular unit 16 of the invention may be formedwith four openings 18 extending in different directions. The neighboringand connected cellular units 16 may communicate with one another throughthe openings 18. However, the number of the openings 18 is notparticularly restricted thereto, and may be adjusted according to theactual requirements without affecting the structural strength. In otherwords, the numbers of the openings 18 formed in different cellular units16 may be the same as or different from one another.

As shown in FIG. 4 or 5, after the flowing air streams contact the heatdissipating body 14, a portion of the air streams contacts with theexternal surface of the heat dissipating body 14 and takes the surfaceheat away, and the other portion of the air streams may enter the heatdissipating body 14 from the opening 18 on the windward surface, and theair streams flow into other cellular units 16 through other openings 18.It is to be noted that the pattern and direction of the arrow representthe schematic flowing direction of the flowing air stream, but does notintend to restrict the substantial flowing direction of the air stream.

According to FIGS. 4 and 5, it is obtained that the air streams, afterentering the heat dissipating body 14, can flow in different directionsand continuously contact the structure surface (heat dissipatingsurface) of each cellular unit 16. Therefore, the air streams flowingout of the heat dissipating body 14 can concurrently take away a portionof heat of each cellular unit 16, so that the temperature of eachcellular unit 16 is decreased and the good dissipation effect isobtained.

On the other hand, as the number of the openings 18 gets more, theselectivity of the air flow directions gets more and the flowing pathgets longer. Thus, the time, during which the air is left in the heatdissipating body 14, is lengthened, and the air streams contact eachcellular unit 16 with the longer time and the higher possibility. Thus,the air streams, flowing out of the heat dissipating body 14, can takemore heat away, so that the heat dissipating body 14 has the betterdissipation effect.

In addition, the more structure surfaces of the cellular unit 16represent that the heat dissipating body 14 may have more surfacesserving as the windward surfaces. Thus, the air streams flowing indifferent directions may enter the heat dissipating body 14 more easily.

As shown in FIGS. 2 and 3, the top edge of the heat dissipating body 14of the invention has the arced or wavy shape, so the air streams,flowing along the top edge of the heat dissipating body 14, can satisfythe streamline movement track, and can thus take away the heat of theheat dissipating body 14 more smoothly.

In the example of FIG. 6 showing the cellular unit 16 constituted by thehexagonal columns, two opposite structure surfaces may be selected, andeach of the selected structure surfaces is formed with an opening 18, sothat the two openings 18 are disposed opposite each other, and theoverall heat dissipating body 14 is formed with a through channel,through which the air streams flow.

As shown in FIG. 7, at least one of the two openings 18 of each cellularunit 16 is selected, and the structure surfaces on two sides of theselected opening 18 are defined as cell walls 36. The wall edge of oneof the cell walls 36 is formed into an arced wall edge 38. Consequently,the opening 18 has a bottom gap and a top gap larger than the bottomgap.

As shown in FIG. 8, another example of the invention is disclosed,wherein a heat dissipating body 14 is formed on the base 12, and theheat dissipating body 14 is composed of a plurality of cellular units 16having quadrilateral column structures. In addition, each structuresurface of the cellular unit 16 is formed with an opening 18 so that theair streams can flow through multiple channels of the heat dissipatingbody 14, and the air streams, after entering the heat dissipating body14, can flow in many directions to enhance the dissipation effect.

As shown in FIG. 9, the heat sink of the invention may be applied to anoutdoor opto-electronic apparatus, such as a LED road lamp 20. Thus, thebase 12 may be an upper lamp shell 22 of the LED road lamp 20, and theheat dissipating body 14 and the upper lamp shell 22 are integrallyformed.

While the present invention has been described by way of examples and interms of preferred embodiments, it is to be understood that the presentinvention is not limited thereto. To the contrary, it is intended tocover various modifications. Therefore, the scope of the appended claimsshould be accorded the broadest interpretation so as to encompass allsuch modifications.

1. An external cellular heat sink structure, comprising: a base; and a heat dissipating body integrally formed on the base, wherein the heat dissipating body comprises a plurality of hollow cellular units, the neighboring cellular units are connected together, and each of the cellular units has at least two openings communicating with the connected cellular units.
 2. The heat sink structure according to claim 1, wherein the cellular unit has a hexagonal column structure.
 3. The heat sink structure according to claim 1, wherein the two openings of the cellular unit extend in different directions.
 4. The heat sink structure according to claim 1, wherein the two openings of the cellular unit are disposed opposite each other.
 5. The heat sink structure according to claim 1, wherein each of two sides of one of the openings of the cellular unit has a cell wall, and a wall edge of one of the cell walls is an arced wall edge.
 6. The heat sink structure according to claim 1, wherein a top edge of the heat dissipating body is formed with an arced structure having two sides and a middle portion higher than the two sides.
 7. The heat sink structure according to claim 1, wherein a top edge of the heat dissipating body is formed with a continuous arced wavy structure.
 8. The heat sink structure according to claim 1, wherein the base is an upper lamp shell of a LED road lamp. 